"As a 27 year-old Lutheran pastor and leader in Germany, in April 1933, Bonhoeffer raised opposition to the persecution of Jews and argued that the Church had a responsibility to act against this kind of policy. Bonhoeffer sought to organize the Protestant Church to reject Nazi ideology from infiltrating the church. This led to a breakaway church – The Confessing Church, which Bonhoeffer helped form with Martin Niemoller. The Confessing Church sought to stand in contrast to the Nazi-supported, German Christian movement.

...Bonhoeffer wrote extensively on subjects of theological interest. This included The Cost of Discipleship, a study on the Sermon on the Mount where he argued for greater spiritual discipline and practice to achieve 'the costly grace.'

'Cheap grace is the grace we bestow on ourselves. Cheap grace is the preaching of forgiveness without requiring repentance, baptism without church discipline, Communion without confession… Cheap grace is grace without discipleship, grace without the cross, grace without Jesus Christ, living and incarnate.' — Dietrich Bonhoeffer, The Cost of Discipleship

[Eventually,] Bonhoeffer was denied the right to speak in public or publish any article. However, he managed to join the Abwehr, the German military intelligence agency. It was within the Abwehr that the strongest opposition to Hitler occurred. Bonhoeffer was aware of various assassination plots to kill Hitler. It was during the darkest hours of the Second World War that he began to question his pacifism, as he saw the need for violent opposition to a regime such as Hitler. Bonhoeffer struggled with how to respond to the evil nature of the Nazi regime.

'The great masquerade of evil has played havoc with all our ethical concepts. For evil to appear disguised as light, charity, historical necessity or social justice is quite bewildering to anyone brought up on our traditional ethical concepts, while for the Christian who bases his life on the Bible, it merely confirms the fundamental wickedness of evil.' — Dietrich Bonhoeffer, Letters and Papers from Prison (1967; 1997)

Within the Abwehr, efforts were made to help some German Jews escape to neutral Switzerland. It was Bonhoeffer’s involvement in this activity that led to his arrest in April 1943. As the Gestapo sought to take over the responsibilities of the Abwehr, they uncovered Bonhoeffer’s involvement in escape plans. For a year and a half, Bonhoeffer was imprisoned at Tegel Military prison.

After the failed bomb plot (attempt to kill Hitler) of July 20th, 1944, Bonhoeffer was moved to the Gestapo’s high-security prison, before being transferred to Buchenwald concentration camp and finally Flossenburg concentration camp.

Even during the privations of the concentration camp, Bonhoeffer retained a deep spirituality which was evident to other prisoners. Bonhoeffer continued to minister his fellow prisoners. Payne Best, a fellow inmate and officer of the British Army, wrote this observation of Bonhoeffer.

'Bonhoeffer was different, just quite calm and normal, seemingly perfectly at his ease… his soul really shone in the dark desperation of our prison. He was one of the very few men I have ever met to whom God was real and ever close to him.'

On April 8th, 1945, Bonhoeffer was given a cursory court martial and sentenced to death by hanging. Like many of the conspirators, he was hung by wire, to prolong the death. He was executed with fellow conspirators such as Admiral Wilhelm Canaris and Hans Oster.

Just before his execution, he asked a fellow inmate to relate a message to the Bishop George Bell of Chichester ‘This is the end – for me the beginning of life.’

Bonhoeffer’s principled resistance to Hitler’s regime was a source of inspiration for other figures such as Martin Luther King and Archbishop Desmond Tutu. Bonhoeffer also shared many ideals with Mahatma Gandhi. (In 1935 he turned down an opportunity to learn in Gandhi’s ashram)"